1. Field of the Invention
The present invention relates to a sustained-release pranoprofen preparation useful as an antipyretic, analgesic, or anti-inflammatory drug.
2. Description of the Background
Among non-steroidal anti-inflammatory drugs, propionic acid compounds typified by pranoprofen, ketoprofen, and ibuprofen exhibit excellently balanced antipyretic and anti-inflammatory effects with less side effects than other non-steroidal anti-inflammatory drugs. These drugs thus are widely used as a first drug of choice in clinics. Especially, pranoprofen is a superior anti-inflammatory drug with a minimal risk of side effects on gastrointestinal tract, which is common to non-steroidal anti-inflammatory drugs due to their special pharmaceutical actions.
A defect of pranoprofen is its short half-life period in blood, requiring the patients to dose the drug 3 times a day, which the patients sometimes feel difficulty to comply with. This is undesirable from the aspect of controlling diseases. Even if its side effect is small, a rapid concentration increase of a drug in blood after oral administration is by not necessarily means safe for patients. Development of a pranoprofen preparation which can safely deliver the effects of pranoprofen over a long period of time is therefore desired.
In view of this situation, the present inventors have undertaken extensive studies and found that the use of an oily component, water-soluble component, water-insoluble component, or intestinally soluble component, as sustained-release components, can effectively control the rate of release of pranoprofen. This finding has led to the completion of the present invention.